This application claims the priority of Korean Patent Application No. 2002-79271, filed on Dec. 12, 2002 in the Korean Intellectual Property Office, which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to an apparatus for collision resolution among home networking stations using carrier sense signals, and more particularly, to an apparatus for collision resolution among home networking stations using Media Access Control (MAC) according to the HomePNA 2.0 specification for constructing home networks.
2. Description of the Related Art
The Home Phoneline Networking Alliance (HomePNA) is a non-profit association of more than a hundred companies working to ensure adoption of a single unified a phoneline networking industry standard.
The HomePNA was founded in June 1998 by 3Com Corporation, Advanced Micro Devices, Inc., AT&T, Wireless Services Corporation, Compaq Computer Corporation, Conexant Systems, Inc., Broadcom Corporation, Hewlett-Packard Company, IBM, Intel Corporation, Lucent Technologies, Rockwell Semiconductor Systems, and Tut Systems. Current participant membership has increased to include companies spanning the networking, telecommunications, hardware, software, and consumer electronics industries.
The HomePNA was founded due to increasing demand for home networking, as a result of the proliferation of multi-functional, interconnected personal computers (PC). In addition, the HomePNA was founded to facilitate sharing of resources among multiple PCs, including network games, peripherals, files, and application programs. The participant members of the HomePNA focus on developing an open standard that ensures interoperability among products from different companies. In addition, the participant members have determined that home networking should operate over a home's existing copper phonelines. Accordingly, the use of existing wiring infrastructure achieves the HomePNA goal of simplifying the construction of home networking.
HomePNA's 1.0 specification was used to construct a local area network interoperable with Ethernet and operate at 1 Mbps without use of a hub, a router, a splitter, or a terminator. A maximum of twenty-five computers, peripherals, and networking devices can connect to the home network via adaptors.
The HomePNA released the HomePNA 2.0 specification on Dec. 1, 1999. The HomePNA 2.0 specification also uses existing phonelines, however, the HomePNA 2.0 specification operates at 10 Mbps. The new specification, while interoperable with the HomePNA 1.0 specification, is designed to provide a faster networking environment capable of supporting voice, video, and data in the future.
Under the HomePNA 2.0 specification, the crucial point of home networking construction is to provide collision resolution among stations that share the network.
In order to provide collision resolution, the HomePNA 2.0 specification uses a collision-resolution algorithm called a Distributed Fair Priority Queuing (DFPQ). When collision occurs among stations having the same transmission priority, the DFPQ determines the data transmission order of the stations.
Since the DFPQ of the HomePNA 2.0 specification uses 4-bit maximum back-off level (MBL) and back-off level (BL) counters, the DFPQ of the HomePNA 2.0 specification can provide collision resolution to a maximum of 16 stations. Since a maximum of 25 stations can be connected in the HomePNA network, a maximum of 25 collisions may occur in the HomePNA network. Thus, the DFPQ of the HomePNA 2.0 specification cannot provide collision resolution for all configurations permitted in a HomePNA network.
In addition, the DFPQ of the HomePNA 2.0 specification counts the number of back-off signals using the MBL counter and the BL counter in the back-off sections. However, when error or ripples of carrier sense signals occur, the use of counters could lead to incorrect calculation of the number of back-off signals. This might result in further loss of resolution from collision,